The present invention is based on a manually operated electric machine tool for a disk-shaped, rotating tool.
In manually operated electric machine tools of this kind, the purpose of the guard is to protect the user from sparks and material particles that are hurled outward from the rotating tool, e.g. a grinding wheel or cutting wheel, during operation. The guard should also protect the user in the event that the tool breaks. For example, when a cutting wheel jams in the work piece, the cutting wheel can shatter. In this case, the guard must prevent fragments of the shattered cutting wheel from coming near the user. Since the guard generally only covers an angular range of 180° of the rotating tool, in order to assure a sufficient degree of protection in various work applications of the manually operated electric machine tool in which the machine is used differently, the guard is designed to be rotationally adjustable. In order to be able to rotate the guard into the desired region, the clamping element, which is usually embodied in the form of a clamping screw, must first be loosened by means of an auxiliary assembly tool, e.g. a screwdriver, and then the guard is set in the desired position by tightening the clamping screw again so that even if the rotating tool breaks, the guard cannot rotate on the collar in reaction to the pressure exerted by the parts of the tool being hurled outward. Adjusting the guard by loosening and tightening the clamping screw with the required auxiliary tool is not only troublesome so that the procedure of adjusting the guard to the proper working position is often omitted, but also, over the long term, subjects the clamping screw to wear so that the guard can no longer be fixed to the collar with a sufficient degree of reliability and no longer assures sufficient protection of the operator if a tool shatters.